So you’re saying that the Confederacy was their own country? Then Lincoln invaded another country without permission from congress.
Nice try, genius.
The fact that the Confederacy, including Virginia, formally declared war on the United States, and had forces operating in Union states (i.e., Missouri) did not make it any less a Rebellion in Lincoln's eyes.
US Federal law covering Rebellions is the 1792 Militia Act, first used by President Washington in 1794 against the Whiskey Rebellion.